Multiple input counter utilizing magnetic drum storage



NOV 23, 1965 M. E. FRANK ETAL 3,219,802

MULTIPLE INPUT COUNTER UTILIZING MAGNETIC DRUM STORAGE Filed Oct. 3,1961 2 Sheets-Sheet l Nov. 23, l965 M. E. FRANK ETAL 3,29302 MULTIPLEINPUT COUNTER UTILIZING MAGNETIC DRUM STORAGE Filed 001'.. 3, 1961 2Sheets-Sheet 2 NPUT SEC/TOR O iNPUT 4 SECTOR l N P LAT VL T- CTOR n 8545 25 \5 DECML OOOO OOO

SPACE Ea lTS R WE BT 4m 2 /P/CHARD E. /QL/SH INVENTORS BY WVLWMV UnitedStates Patent O 3,29t32 MULTEPIJE NPUIF CUNTER UTIUZIG MAGNETEC DRUMSTGRAGE Marvin E. Frank, Canoga Parli, and Richard E. Rush, GranadaHills, (Iaiiil, assignors, by mesne assignments, to The Bonner-RamoCorporation, Stamford, Conn., a corporation o Delaware iiied Oct. 3,1%1, Ser. No. 142,6g i Ciaims. (Sl. 23S-92) This invention relates tocounting systems in general and more particularly to a multiple inputelectronic counting system utilizing a moving magnetic memory for countstorage.

In many industrial and commercial environments, there is a need forcounting. For instance, in a manufactoring plant, a count must often bemaintained of manufactured parts as they flow through a productionsystem. In warehousing, a count must ideally be kept of each individualitem as stock is added or subtracted in inventory. In a steel stripmill, an accumulated count is normally maintained for each of severaldefects measured in a moving steel strip. In an automobile traflccontrol system, a count normally must be maintained of traiiic iiow onseveral streets. In atomic energy facilities, counters continuouslymonitor radiation at different points in a process or at diiferentlocations in the plant. In the collecting of tolls on toll roads,bridges and tunnels, a` count of several diiferent types of vehicles ineach of several lanes must be maintained. It is therefore apparent thatthere is hardly an area in which things are manufactured, moved orhandled where counting is not a requisite part of the system.

In many of these applications, it is desirable to obtain a cross totalof some of the counters or to sort the accumulated counts of thecounters into various categories. For example, an automobile productionplant may turn out automobiles of ten different models. Fenders may beon one line, hoods on another, wheels on the third, etc. For purposes ofproduction control the number of items produced in a speciiied period oftime on any particular line must be known. Information as to the type offender, hood, etc. being produced is also necessary. If a productioncontrol manager has immediate access to all of this data, he can betterexercise control over the various phases of the operation. Thus, even inthis simplilied example, there may be twenty different parts beingmanufactured, each in five different types, requiring, for instance,counts of one hundred categories.

At the present time, the most widely used counters in industry are ofthe mechanical or electromechanical type wherein an accumulated count isvisually presented. These units are simple, ruged and reliable. Thistype of counter is usually capable of registering approximately tencounts per second while some extremely specialized units currentlyavailable can register up to sixty counts per second with fairly goodreliability. For higher counting speeds, in the range of one hundred toone million counts per second, wide use is made of electronic counterssuch as an electronic sealer. Oriinally, these electronic scalers weredeveloped for use in atomic energy applications. However, they are nowutilized in many other industrial applications. Another type of counterwhich has been developed for ultra-high speed counting applications at,for instance, rates up to a megacycle employs a multiple element vacuumtube known as a beam switching tube.

ICC

For applications which lie in the area between the relatively slow speedapplications which are implemented by electromechanical counters and theultra-high speed counting applications which are implemented byelectronic scalers, a number of ingenious devices have been developed.One such example is a glow transfer tube which has a single envelopecontaining ten anodes, an arrangement whereby an electron beam from acommon cathode is sequentially stepped from anode to anode, thus formingthe basis for a counting device. The counting range of this type deviceis usually from zero to two thousand cycles. However, they are mostoften utilized in applications of from one hundred to several thousandcycles per second. Additionally, this type of counting device providesan electrical readout.

With the recent advent of automatici-i, a need has arisen for electricalreadout of the various counters utilized in the particular process beingautomated. This facility is necessary for eicient utilization of theassociated computing device in the automated process in that valuablecomputer time is wasted where the various counters are visually read andtheir counts punched or otherwise manually entered into the computingdevice.

Electronic counters provide electrical readout in that the digitalquantity stored in the counter can be read out electrically to anexternal printer, tape or card punch or computing device. Since most ofthe counter applications in industry are in areas requiring relativelyslow counting, an attempt has been made by several manuacturers of themechanical and electromechanical type counters to fill the need forelectrical readout by equipping the counter wheels of the counters withindividual commutator discs which provide an electrical code equivalentof the count in the particular counter wheel involved to associatedbrushes which are electrically connected to an associated printer, taperecord punch, etc.

However, none of the above-mentioned type counters have proved to beentirely satisfactory for use in applications where electrical readoutis necessary. For instance, in those applications where relatively slowcounting speed of the mechanical or electromechanical type counter canbe tolerated, the associated commutator and brush a1'- rangernent whichis necessary for electrical readout reduces the otherwise highreliability of the counter since the brush and commutator arrangement,because of the large number of sliding contacts, is not only subject tomechanical and electromechanical wear, but, in addition, is prone tomalfunction due to the large amount of air impurities which are oftenfound in many industrial facilities. Until recently, most electroniccounters or scalers have used vacuum tubes, four vacuum tubes beingrequired per decade. A typical counter of this type would, therefore,have 'twenty-four vacuum tubes exclusive of those in the power supplyand miscellaneous circuits. Reliability of these devices is limited,therefore, by the nite life characteristics of the vacuum tubes.Recently, counters of this type using transistors have become available;very recently, the advent of high speed transistors has permittedconstruction of completely solid state counters with far longer life andgreater reliability than was heretofore possible. The cost of thesesolid state counters has tended to be quite excessive.

Another problem encountered when electromechanical counters are utilizedalong with an electrical readout capability is that of the ambiguitywhich exists in the counter output during the moment of transfer fromone number to the next. In the case .of most electromechanical counters,this transfer occupies an appreciable portion of the count cycle. Sincethe counter cannot be read out during this transition, a suitable signalgate must, therefore, be provided to inactivate the output during thistime. Although the electromechanical visual readout counters arethemselves inexpensive, provision of readout commutators ad-dsconsiderably to their cost. Thus, often where electrical readout isprovided, the cost of the counter is eight times the cost of anidentical counter without the electrical readout capability. In additionto the cost of the counter, the cost of wiring ten leads to each of theten segments representing the output of a single decade is appreciable.Where large numbers of counters are required, the cost of cabling can bea signicant item.

Electronic counters are quite expensive. However, where only a fewdifferent items are to be counted, the cost of these units can bereadily justified. However, where large numbers of counters arerequired, the cost often becomes staggering. For instance, a typicalstrip mill opera-tion may require fifteen or twenty counters capable ofcounting at a rate of about 100 counts per second. A warehouse inventorysystem might require several thousand counters capable of counting at arate fof one count per second. In a toll bridge data collect- 'ingsystem 1,000 to 2,000 counters are required. Each counter, however, canbe quite slow since vehicles cannot pass the toll booth much faster thanone every three seconds.

It is evident that for an application requiring a large number ofcounters, the use of individual commercially available counters willresult in an expensive system. It is, therefore, an object of thepre-sent invention to provide a novel counting sys-tem which is capableof accepting a plurality of count inputs.

Another object of the present invention is to provide a relatively highspeed counter which is extremely reliable and entirely solid state.

Another object of the .present invention is to provide a counting systemwherein additional count inputs can be added at a minimum cost.

Another object of the present invention is to provide a novel method ofcounting which is particularly suited for use with moving magneticmemory type digital computers.

Other and further objects and advantages of the present invention willbecome apparent to one skilled in the art from a consideration of thefollowing detailed description when read in light of the accompanyingdrawings, in which:

FIG. l is a block diagram of the novel counting systernherein-described;

yFIG. 2 is an AND-OR gate combination which may be used for inputselection; and

FIG. 3 is a chart showing the binary equivalents of the decimal numbersthrough 9.

FIG. 4 is a chart showing the digit format of a `drum sector.

Brieiiy, an input system is utilized which sequentially samples -aplurality of inputs. A counter register recorded on a magnetic drumholds the accumulated count associated with each input. The content ofeach of the counter registers is continuously read and -circulatedthrough yassociated add one circuitry wherein a one is added to thecontents of the particular register if its associated input is true. Theoutput of the add one circuit is re-recorded in the exact memorylocation that the register occupied prior to reading.

Refer first to FIG. 1. In FIG. 1 is generically shown input means 1having a stepping arm 2 which is capable of sequentially stepping frominput 3 through input n. lEach o-f the inputs 3 through n is connectedto sensing means (not shown) which provide an electrical impulse onlines 3 through n concurrently with the detection by each sensing meansof a count. The `form of the sensing means, which may be a photocell, aninfrared detector, a mechanical feeler, etc., is not important for thepurpose of the present invention, the particular form depending upon theparticular application involved.

While the input means 1 is shown in the form of a stepping switcharrange-ment, this is for convenience only and it should be understoodthat the input means may be of any form, the speed of which iscompatible with the hereindescribed counting system. For instance, theinput means -may take the form of the AND-OR arrangement of FIG. 2wherein a plurality of diode-resistor AND gates drive a diode-resistorOR gate. The AND gates have two input terms which are connected to thecount sensor and a timing signal identifying the parti-cular sector ofthe drumV which is passing under the read head, as will hereinafter bemore fully explained. The OR gate will have an -output at any time thateither of the plurality of AND gates is true.

The output of the input means 1 is fed along line 4 to a data flip-flop5 (FD). The output of the data flipflop FD is fed along line 6 to theinput D28 of a delay register 9. The output of FD is also fed alonglines 10 and 11 to the input of a carry flip-hop 12 (FC). The output ofthe carry iiip-flop FC is fed along line 13 to the input D28 of thedelay register 9. The input stage D28 -of the delay register 9 has itsoutput connected to the input of the next succeeding stage D27 which inturn has its output connected to the input of the next succeeding stageD26, etc. The output stage D24 has its output connected along line 15 tothe input of the write nip-flop 16 (FW). The output of FW is fed alongline 17 into the write amplifier 18. The output of the write amplifier18 (WA) is fed along line 19 to the write head 20 which is in magneticassociation with the magneti-c drum 21. Also in magnetic -associationwith magnetic drum 21 is a read head 22 which is physically separatedfrom the write head 20 seven binary digits. The write and read heads arepreferably contained in la single housing. `One such head is the subjectof a copending application entitled, Electromagnetic Delay Head, SerialNo. 115,537, assigned to the same assignee as the assignee of thepresent invention. A read ampliiier 24 has its input connected to theread line 23 which in turn is connected to the read head 22. The outputof the read amplifier (RA) is fed along `line 25 to the input of theread iiip-op 26 (FR). The output of FR is fed along 14 to the input D28of the delay register 9. The output of FR is also fed along line 27 toline 11 and thence to the input of FC.

Refer next to the chart of FIG. 3 wherein is shown the binaryequivalents of the decimal numbers O through 9. From a closeconsideration, it `can be seen that a simple rule for adding one to anumber can be devised. For instance, it is seen that in considering thebinary number 0010, it can be incremented by one by inverting the 0contained in the 1s column and copying the 1 contained in the I2s columnand the 0 contained in the 4s and 8s columns. Considering binary number0011, it can be seen that it can be incremented by a 1 by inverting the1 in the 1s column, inverting the 1 in the 2s column, inverting the 0shown in the 4s column and copying the 0 contained in the 8s column.'Ihus the rule for adding one may be stated as follows: Consideringsequentially the number to be incremented by 1 beginning with its leastsignificant digit, invert all digits through and including the first 0and thereafter copy each digit as is. This rule is implemented alongwith a method of digital filtering to prevent the counting of random orspurious noise pulses as hereinafter described.

The logical terminology hereinafter employed is as follows: A jsubscript means that if the conditions on the right of the equalitymarks are met, the left-hand term is set in its true or one state duringthe following digit time while a subscript k implies the false or zerostate; DT designates timing, thus DTI-24 signifies digit times 1-24;capitol letters such as FC imply a true or one condition while capitalletters primed as RA imply a false or zero condition.

Consider again FIG. l. For the purpose of illustration of operation, thedescription of the operation involved in adding one to a drum registeras well as digital iltering will be described. In the present example itwill be assumed that each of the drum sectors is 28 bits in length andthat 24 of the 28 digits are used for the counter and two of the fourspace bits are used as control bits to accomplish the hereinafterdescribed digital filtering. Thus each sector may be broken down asshown in FiG. 4. It is, of course, apparent that this operation is thesame for any of the drum registers. Assume, therefore, that there is aninput along line 4 which corresponds in voltage to the logical level ofa binary one utilized in the system which is indicative of the sensingof one of whatever article is being counted.

From a consideration of FIG. 4, it can be seen that the control bitsassociated with each counter register occur at DT27, 28 preceding .thereading `of the particular register by the read head. Thus, inaccordance with the digital filtering method, FD is set to O eachDT25( 1) preceding the entry of the particular sector involved and FD isset true at each DT26 (2) in the event that there is a one on the inputline 4.

FC is utilized in both the add one operation whereby the contents ot aparticular drum register are increased by one and the digital filteringwhereby spurious noise pulses are digitally iiltered and prevented frombeing registered as a count on the input line 4.

Considering first the add one operation in accordance with the logicalEquation 3 associated with the delay register 9 which is merely a shiftregister (4)-(7), it can be seen that FC controls the add one operation.If FC is true at DTl, the input stage D28]- of the delay register 9copies FR until the lirst one occurs (3). Upon the occurrence of theiirst one, FC, as will hereinafter be described, is reset and D28]-copies FR through DT24(3). Thus one is added to the contents of theselected sector if FC is true at DTI.

A measure of noise filtering is accomplished by imposing the requirementthat any input along line 4 must be present for two drum revolutions.Assume that FD is false for several drum revolutions at DT25 precedingthe selector sector. Zeros are copied by D28, at D27 from FD(8) and atD28 from FC(9). The iirst revolution that FD is true at DT26, a one iscopied at DT27 from FD by D28j(3) and a zero is copied by D281 from FCat DT 28(9). Thus FC is false at DTI and the contents of the selectedsector are not incremented by one. During the second revolution that FDis true at DT26, a one is copied by D28,- at DT27 from FD(3) and FC isset true at DT27(lO). D28,- tben copies a one from FC at DT28(3) andsince FC is true at DTI, the contents of the selected sector areincreased by one during the interval DTl through 24(3), (11). Onsubsubsequent revolutions, if FD is still true. FC is set true at DT27and FC is reset at DT28(12). A one is copied by D28,- at D27 from FD ana zero is copied at D28 from FC(3). During the tirst revolution that FDis false, a zero is copied by D283 at DT27 and FC is not set true atDT27(l0). Thus a zero is copied by D281 at D28 from FC. During thesecond revolution that FD is false, the cycle described above may berepeated. Line 4 must, therefore, be true for at least two drumrevolutions before the counter contents can be changed. Random noisepulses thus tend to be rejected.

As is obvious from a consideration of the logical equations associatedWith FC, it can be seen that FC is set true at DT27 only if FD and FRare true (l0), FR, of course, being true only if a one is entered inD28, during DT27 of the previous revolution. FC is reset at DT28 if FCand FR are true (l1), which indicates that one has already been added tothe contents of the particular register due to the presence of the inputsignal on line 4. Likewise FC is set to zero at DTI through 24 in FR istrue or at DT24 in the special case that the counter fills and FR' doesnot go true (11). The remaining logical elements in the system simplycopy their preceding element as indicated by the logical equationsassociated with FR, FW, and the delay register 9.

In some applications, it may be desirable to count through use ofsubtraction rather than by addition. The logic at D28, is unchanged butone FCk input term changes from: FR.DT124 to FR.DT1-24(11s. D28, thuscopies FR until the first zero occurs and then FC is reset. D281 thencopies FR. Thus the contents of the counter are decreased by one if FCis true at DT1. While the present description has been made throughutilization of only one drum sector, it is, of course, apparent that aplurality of sectors could be utilized. Each track on a computercontains a plurality of sectors, the number of which depends upon thelength of the sector. The sector selection means involving magneticdrums are old in the art as well as track selection means. Thus itshould be understood that the present invention is not limited to onesector or a plurality of sectors upon the same track.

Likewise, the particular digit timing means involved in the presentinvention has not been described since digit timing means are well knownin the art and are readily available. Thus timing means are alwayspresent in a computer and it is a simple matter to provide such a timingmeans in the event that the counter is employed in non-computer typeapplications.

In the above described manner we have presented a novel counting systemwhich is capable of accepting a plurality of count inputs. Furthermore,I have provided a novel counting system which not only can be designedto function independent of computer applications but which is highlycompatible in computer applications to provide a counting system ofextremely low additional cost beyond the cost of the computer system.

While there has been described what is at present considered to be apreferred embodiment of the invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing 'from the invention, and it is aimed in theappended claims to cover all such changes and modifications as fallwithin the true spirit and scope of the invention.

What is claimed is:

1. A counting system for counting and separately maintaining theindividu-al counts from a plurality of input sensors comprising: amoving magnetic medium having associated therewith in magneticassociation at least one read head and one write head, readamplification means .and write amplification means attached to said readand write heads, delay means connected between said read and writeamplification means, said delay means comprising a read flip-nopconnected to said read amplitication means, la delay register having aninput stage and an output stage having its input stage connected to saidread Hip-flop, a write flip-flop, the output stage of said delayregister being connected to said write flip-Hop, the output of saidwrite dip-tiop being connected to said write amplification means, inputmeans for selecting from among said plurality of count sensors, addingmeans connected between said input means and said delay means for addingone to the contents of said delay means in the event that an input isreceived from the selected count sensor, said adding means comprising adata flip-flop having an input and an output, and a carry Hip-flop, theoutput of said data flip-flop being connected to the input of said carrytlip-op, the output of said read flip-flop being connected to the inputof said carry flip-tlop and the output of said carry tlip-tiop beingconnected to the input stage of said delay register.

2. A counting system for counting and separately maintaining theindividual counts from a plurality of input sensors comprising: a movingmagnetic medium having associated therewith in magnetic association-at-least one read head and one write head, read amplification means andwriteramplification means attached Vto said read and Write heads, delaymeans connected between said read and write amplification means, said`delay means comprising a read fiip-fiop connected to said readamplification means, a delay register having `an input stage and anoutput stage having its input stage connected to said read iiip-tiop, awrite fiip-fiop, the output stage of said delay register being connectedto said Write tiip-op, the output of said write iiip-fio-p beingconnected to said write amplification means, input means for `selectingfrom among said plurality of count sensors, adding means connectedbetween said input means and said delay means for adding one to thecontents |of said delay means in the event that an input is receivedfrom the selected count sensor, the electrical delay provided by saiddelay means being equal to the physical delay provided by said read andWrite heads whereby information read from a particular sector of themoving magnetic medium is re-recorded in exactly the same sector, andsaid adding means comprising a data flip-fiop having an input and anoutput, and a carry flip-flop, the output of said data flip-flop beingconnected to the input of said carry flip-flop, the output of said readfiip-flop being connected to the input of said carry iiip-fiop and theoutput of said carry flip-flop being connected to the input stage ofsaid delay register.

3. A counting system for counting and separately maintaining lthe totalindividual counts from a plurality of count sensors comprising: a movingmagnetic medium having at least one read head and at least one writehead associated in magnetic association therewith, read amplificationmeans having an input and an output, the input of said readamplification means being connected to said read head, a read flip-flophaving an input and an output, thc output of said read amplificationmeans being counected to said read flip-fiop, a delay register having aninput and an output stage, the output of said read fiip-fiop beingconnected to said input stage, a Write flip-fiop having an input and anoutput, the output stage of said delay register being connected to theinput of said Write iiip-fiop, a write amplification means having aninput and an output, the output of said write fiip-iiop being connectedto the input of said Write amplification means, the output of said writeamplification means being connected to said write head, input meanscapable of selecting from among said plurality of count sensors, digitalfiltering and adding means connected to said input means comprising adata fiip-fiop having an input and an output, the input of said dataiiap-op .being connected to the input of said carry fiip-iiop having aninput and an out-put, the output of said data ip-iiop being connected tothe input of said carry fiip-iiop and the input stage of said delayregister, the output of said carry flip-flop also being connected to theinput stage of said delay register, and the output of said readflip-flop being connected to the input of said carry fiip-flop wherebythe contents of the delay register are implemented by one and the datafrom the count sensor is filtered in accordance with the logicalequations:

4. A counting system for counting and separately maintaining the totalindividual counts from a plurality of count sensors comprising: a movingmagnetic medium having at least one read head and at least one Writehead associated in magnetic association therewith, read amplificationmeans having an input and an output, the input of said readamplification means being connected to said read head, a read flip-ophaving an input and an output, the output of said read amplificationmeans being connected to said read iiip-fiop, a delay register having aninput and an output stage, the output of said read fiip-iiop beingconnected to said input stage, a write fiip-iop having an input and anoutput, the output stage of said delay registerrbeing connected to theinput of said Write flip-flop, a write amplification means having aninput and an output, the output of said write fiip-fiop being connectedto the input of said write amplification means, the output of said writeamplification means being connected to said Write head, the totalelectrical delay encountered in said read amplifier, read fiip-flop,delay register, Write flip-flop and write amplifier being equal to thetotal physical delay presented by said read and write heads, input meanscapable of selecting from among said plurality of count sensors, digitalfiltering and adding means connected to said input means comprising adata dip-flop having an input and an output, the input of said dataiiip-fiop Vbeing connected to said input means, a carry flip-flop havingan input and an output, the output of said data flip-flop beingconnected to the input of said carry ip-fiop and the input stage of said`delay register, the output of said carry fiipflop also being connectedto the input stage of said delay register, and the output of said readflip-flop being connected to the input of said carry iiip-iiop wherebythe contents. of Vthe delay register are implemented by one and the datafrom the ,count sensor is filtered in accordance with the logicalequations:

References Cited by the Examiner UNITED STATES PATENTS ROBERT C. BAILEY,Primary Examiner.

DARYL W. COOK, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,219,802 Novmber 23, 196

Mervin E. Frank et al.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent 'should read ascorrected below.

Column 5, line 58, for "an" read and line 71, for "D28i" read D28 column6, line 2, for "in", first occurrence, read if line 9, for "DZS" readDZSj line l0, for "D28" read D28j line l2, for "D281" read D28]- Column7, line 50, for "the input of said" read said input means a Signed andsealed this 19th day of September 1967.

(SEAL) Attest:

ERNEST W. SW'IDER Attesting Officer EDWARD J. BRENNE Commissioner ofPatent:

1. A COUNTING SYSTEM FOR COUNTING AND SEPARATELY MAINTAINING THEINDIVIDUAL COUNTS FROM A PLURALITY OF INPUT SENSORS COMPRISING: A MOVINGMAGNETIC MEDIUM HAVING ASSOCIATED THEREWITH IN MAGNETIC ASSOCIATION ATLEAST ONE READ HEAD AND ONE WRITE HEAD, READ AMPLIFICATION MEANS ANDWRITE AMPLIFICATION MEANS ATTACHED TO SAID READ AND WRITE HEADS, DELAYMEANS CONNECTED BETWEEN SAID REAR AND WRITE AMPLIFICATION MEANS, SAIDDELAY MEANS COMPRISING A READ FLIP-FLOP CONNECTED TO SAID READAMPLIFICATION MEANS, A DELAY REGISTER HAVING AN INPUT STAGE AND ANOUTPUT STAGE HAVING ITS INPUT STAGE CONNECTED TO SAID READ FLIP-FLOP, AWRITE FLIP-FLOP, THE OUTPUT STAGE OF SAID DELAY REGISTER BEING CONNECTEDTO SAID WRITE FLIP-FLOP, THE OUTPUT OF SAID WRITE FLIP-FLOP BEINGCONNECTED TO SAID WRITE AMPLIFICATION MEANS, INPUT MEANS FOR SELECTINGFROM AMONG SAID PLURALITY OF COUNT SENSORS, ADDING MEANS CONNECTEDBETWEEN SAID INPUT MEANS AND SAID DELAY MEANS FOR ADDING ONE TO THECONTENTS OF SAID DELAY MEANS EVENT THAT AN INPUT IS RECEIVED FROM THESELECTED COUNT SENSOR, SAID ADDING MEANS COMPRISING A DATA FLIP-FLOPHAVING AN INPUT AND AN OUTPUT, AND A CARRY FLIP-FLOP, THE OUTPUT OF SAIDDATA FLIP-FLOP BEING CONNECTED TO THE INPUT OF SAID CARRY FLIP-FLOP, THEOUTPUT OF SAID READ FLIP-FLOP BEING CONNECTED TO THE INPUT OF SAID CARRYFLIP-FLOP AND THE OUTPUT OF SAID CARRY FLIP-FLOP BEING COINNECTED TO THEINPUT STAGE OF SAID DELAY REGISTER.